Litter box mat



FIG. 1 is a perspective view of the litter box mat showing the new design;

FIG. 2 is an end view thereof;

FIG. 3 is a left side elevation view thereof; and,

FIG. 4 is a top plan view thereof.

The right side is a mirror image of the left side;

The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a litter box mat, as shown and described. 